Module 3: Toxicology - Section 9: Organic Solvents

TOX 9.2: Lecture: Health Effects of Organic Solvents

CLASS EFFECTS:

Effects common to most solvents.

1. Respiratory irritation:

   This is often overlooked. Workers may complain of their eyes and noses running, sore throat, burning chest and cough.

2. Central neurological effects:

   With short-term relatively high exposures, headaches, mild euphoria, dizziness, nausea, fatigue.

3. Dermatitis:

   Defat skin, may cause irritant contact dermatitis.

SPECIFIC EFFECTS:

Effects specific to one or more individual solvents.

Central Nervous System

Acute:

Euphoria, disinhibition Light-headed “dizzy” Headaches, nausea, fatigue
	Impaired judgement
Depressed consciousness, seizures
	Impaired performance
[Note: solvent sniffing (glues, petrol)   absorb toluene, n-hexane, petrol, lead]
	Impaired postural stability

Prognosis: Reversible.

Chronic

• Encephalopathy (diffuse brain effect)
      Mood, concentration, memory disturbance
• Vestibular effects (?interaction with TB drugs)

Prognosis: Reversible in early stages.

Peripheral Nervous System:

n-Hexane Methyl-n-butyl ketone Solvent addiction		hexanedione
		sensorimotor (ascending) neuropathy

Prognosis: partially/wholly reversible.

Kidney

Acute tubular necrosis:

Halogenated solvents Glycols Glycol ethers Toluene Petroleum distillates Dioxane

* High exposure    * Short latency    *Rx ® Recovery

Chronic glomerulonephritis:

• Literature inconsistent
• Solvents not specified

Mild tubular, glomerular dysfunction:

E.g. tubular enzymes in urine.

Liver:

Acute/subacute/high exposure: carbon tetrachloride Chloroform, etc.		acute necrosis + steatosis
Chronic exposure Perchloroethylene Other halogenated solvents Dimethylformamide		raised enzymes: AST ALT

Differential diagnosis:

• Alcoholic liver disease (may be cofactor)
• Fatty liver disease (steatosis)
• Infective liver disease

Control:

• Biological monitoring (problem of sensitivity/specificity)
• Awareness of skin exposure
• OELs

CANCER:

1. Benzene (not Benzine!)

   Aplastic anaemia
   Leukaemia ?/ lymphomas (10 yr ave. latency)

2. Bischloromethyl ether (BCME)
   Chloromethyl / methyl ether (CMME)

   Lung cancer

3. Epichlorhydrin

   ? site

4. Halogenated solvents

   Cancer in animals (? Humans)

REPRODUCTION:

1. Teratogenesis

   Most solvents cross placenta
   ? Effects on foetus

2. Spontaneous abortion

   ? Risk (ethylene oxide)

3. Semen quality

   Glycol ethers decreased sperm counts

Postgraduate Diploma in Occupational Health (DOH) - Modules 3: Occupational Medicine & Toxicology (Basic) by Profs Mohamed Jeebhay and Rodney Ehrlich, Health Sciences UCT is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.5 South Africa License. Major contributors: Mohamed Jeebhay, Rodney Ehrlich, Jonny Myers, Leslie London, Sophie Kisting, Rajen Naidoo, Saloshni Naidoo. Source available from here. For any updates to the material, or more permissions beyond the scope of this license, please email healthoer@uct.ac.za or visit www.healthedu.uct.ac.za. Last updated Jan 2007.
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